1. Field of the Invention
The present invention relates to a scroll compressor used to compress refrigerant gas and the like.
This application is based on Japanese Patent Application No. 2006-164678, the content of which is incorporated herein by reference.
2. Description of the Related Art
Heretofore a scroll compressor is known as a compressor which compresses a fluid gas such as refrigerant gas or the like.
In this kind of scroll compressor a thrust slide bearing is provided which slides against an outer face of an end plate formed by a slide face of an orbiting scroll member, to support a thrust load acting on the orbiting scroll member. This thrust slide bearing is a thrust plate formed from a ring-shaped thin steel plate with a coating film of solid lubricant applied to the slide face, and is attached to a thrust bearing face formed on the housing side. (For example, see Publication of Japanese Patent No. 3364016, FIG. 1).
Furthermore, a fluid machine has been proposed in which a resin coating principally composed of fluororesin and polyamideimide resin is formed on one or both sides of a slide face of a structural member. That is, by specifying the principal components and component ratio combined to form a film with a fluororesin base, formation of a highly reliable resin film in which cracking and peeling do not occur over a long period of time becomes possible. (For example, see Japanese Unexamined Patent Application, Publication No. 2005-325842, FIG. 2).
Incidentally, in a thrust plate (thrust slide bearing) which supports the slide face of an orbiting scroll member, when a coating of a fluororesin such as PTFE is applied to the steel plate with the aim of improving lubrication, peeling of the coating becomes a problem. Hereunder the problem of peeling will be specifically explained with reference to the drawings.
In FIG. 5, reference numeral 27 denotes an orbiting scroll member, which is disposed inside a front housing 5 constituting a low pressure side. In the orbiting scroll member 27, a rear face of an end plate 27A forms a slide face 61, and this is supported and slides on a thrust plate 51 which is fixedly installed on a thrust bearing face 5B of the front housing 5.
As shown in FIG. 6A and FIG. 6B for example, the thrust plate 51 is one where a coating layer 51b of fluororesin or the like is formed on the surface of a ring-shaped thin steel plate 51a. This coating layer 51b receives a repetitive thrust load from the sliding orbiting scroll member 27. Therefore, both corner portions in particular are in danger of peeling off. That is, both corner portions of the thin steel plate 5a are parts where it is difficult to form the coating layer 51b to a satisfactory uniformity. For example, as shown in FIG. 7A, because the coating layer 51b does not adhere easily, separation occurs at the corners, or as shown in FIG. 7B, it is easy for the coating layer 51b to become too thick when the amount of adhesion is increased in order to prevent separation.
From this background, in a scroll compressor, it is desirable to prevent peeling of the coating layer 51b applied to the thrust plate 51, to thereby maintain a desired level of lubrication over a long period of time and thus increase reliability and durability.